c# - word cursor is on的获取方式，在WPF RichTextBox控件中

Question

我想知道如何在 WPF RichTextBox 中获取当前光标所在的单词。我知道 RichTextBox 具有选择属性。但是，这只会给我在 RichTextBox 中突出显示的文本。相反，即使整个单词未突出显示，我也想知道光标所在的单词。

如有任何提示，我们将不胜感激。

Answer 1

将此函数附加到任意 RichTextBox，现在称为 testRTB，并查看结果的输出窗口:

private void testRTB_MouseUp(object sender, MouseButtonEventArgs e)
{
        TextPointer start = testRTB.CaretPosition;  // this is the variable we will advance to the left until a non-letter character is found
        TextPointer end = testRTB.CaretPosition;    // this is the variable we will advance to the right until a non-letter character is found

        String stringBeforeCaret = start.GetTextInRun(LogicalDirection.Backward);   // extract the text in the current run from the caret to the left
        String stringAfterCaret = start.GetTextInRun(LogicalDirection.Forward);     // extract the text in the current run from the caret to the left

        Int32 countToMoveLeft = 0;  // we record how many positions we move to the left until a non-letter character is found
        Int32 countToMoveRight = 0; // we record how many positions we move to the right until a non-letter character is found

        for (Int32 i = stringBeforeCaret.Length - 1; i >= 0; --i)
        {
            // if the character at the location CaretPosition-LeftOffset is a letter, we move more to the left
            if (Char.IsLetter(stringBeforeCaret[i]))
                ++countToMoveLeft;
            else break; // otherwise we have found the beginning of the word
        }


        for (Int32 i = 0; i < stringAfterCaret.Length; ++i)
        {
            // if the character at the location CaretPosition+RightOffset is a letter, we move more to the right
            if (Char.IsLetter(stringAfterCaret[i]))
                ++countToMoveRight;
            else break; // otherwise we have found the end of the word
        }



        start = start.GetPositionAtOffset(-countToMoveLeft);    // modify the start pointer by the offset we have calculated
        end = end.GetPositionAtOffset(countToMoveRight);        // modify the end pointer by the offset we have calculated


        // extract the text between those two pointers
        TextRange r = new TextRange(start, end);
        String text = r.Text;


        // check the result
        System.Diagnostics.Debug.WriteLine("[" + text + "]");
}

根据您是否希望保留数字，将 Char.IsLetter(...) 更改为 Char.IsLetterOrDigit(...) 或其他适当的内容。

提示:将其提取到单独程序集中的扩展方法中，以便在需要时访问它。